Chick that is laying weird

My fiance's mom got a bunch of little chicks and she has one that is laying funny. He is laying face down in his bedding with his wings spread out. She got worried because he is smaller than the rest, despite him being born at the same time as all of them. Hes black and grey with a yellow beak, and a little puffy top on his head. He's also got brown spots on his wings. They keep calling him a him but they aren't too sure what gender he is or even what breed.

Anyways, she separated him from the others because she was worried about him laying like that and possibly getting stepped on by the bigger chicks. I was wondering if this was a normal laying behavior. He doesn't seem like he's sick or anything, he's just laying weird.